There is a brief window of opportunity remaining to see the excellent exhibition at Bletchley Park into codebreaking during World War One, before it closes at the end of the year. Prominent in this activity was Major Malcolm Hay of Seaton, an academic in civilian life, who was severely wounded at the Battle of Loos and subsequently worked in the cryptography field. There is a room in the exhibition dedicated to Major Hay, whose grandson, the present Malcolm Hay of Seaton, is the current Clan Hay Commissioner.
The following description is drawn from the Bletchley Park Website, published here with permission:
The first major exhibition to explore codebreaking in World War One

Major Hay's grandson Angus Hay at the exhibition
The Road to Bletchley Park, sponsored by BAE Systems and Ultra Electronics, celebrates the pioneering achievements of those who waged a secret war – and how they paved the way for the Codebreakers of World War Two.
The story of signals intelligence in WW1 is an untold but crucial one, because a large number of those involved went on to work with the newly formed Government Code and Cypher School (GC&CS) in 1919, which then relocated to Bletchley Park in 1939. Sarah Ralph, Bletchley Park’s WW1 Exhibition Research Coordinator, says “Their efforts from 1914 to 1918 allowed the Codebreakers to hit the ground running at the outbreak of WW2.”
The first phase of this fascinating exhibition, now open in the Block C Visitor Centre at Bletchley Park, introduces the two very separate codebreaking organisations working in WW1: MI1(b), set up by the War Office, and Room 40, established by the Navy. They were each fighting a secret war, behind the scenes in London offices.
The work of these two distinct organisations, each with their own hierarchies and objectives, was dependent on what was then brand new technology. One key exhibit is a replica of a Marconi crystal receiver listening set. Sarah adds “Both Allies and Central Powers used cable and wireless telegraphy to intercept messages and deduce enemy tactics and positions. Each side tried to break the other’s codes and gain valuable intelligence.”
The exhibition also delves into some of the key characters involved in codebreaking during both wars. Sarah says “One of my favourite exhibits related to the work in Room 40 is a copy of Jane’s Fighting Ships. I love this book. It’s an exhaustive catalogue of every nation’s warships. Every time a ship was sunk (Room 40 staff) would cross out the name. It’s a very physical way of marking the conflict’s progress.”
CEO of the Bletchley Park Trust, Iain Standen says “We hope this exhibition, which runs until 2020, will help to shed light on a hitherto less well known story of WW1. As the title of the exhibition alludes to, the work of Room 40 and MI1(b) in WW1 laid the foundations of the success of Bletchley Park in WW2. Visitors will learn how these pioneers operated, and how their work led to the formation of the Government Code and Cypher School, the organisation that eventually set up Bletchley Park.”